Wow your CFS is a lot like mine. I get chest pains, sensitivity to heat, pain behind my right eye, hypersomnia, twitches/tremor, concentration/memory problems, right jaw pain, blurry vision, tinnitus, constipation.
May I ask, do you also get some weird triggers for fatigue, such as doing very light work at a job, or driving for 1+ hours? Does pushing past fatigue cause heart rhythym disruption, and feelings of inflammation in your upper chest? These are characteristics of my fatigue.
I'm male unlike you though.
Phenibut at doses of 2-3 g 100% cures my CFS.
As I start feeling the effects of the drug, I notice a lot more circulation and feelings of blood flow around my gut and intestines. Vision gets clear, gut motility increases, mind clears etc.
I think that the problem is caused by some type of calcium channel upregulation/dysfunction. Overactivity of certain ion channels can cause blood vessels to contract lowering microcirculation, neurons to fire, muscles to twitch. Then cell metabolism problems start from lack of blood flow and constant tension, inflammation starts etc. Perhaps it is caused by a virus, because the issue for me started in my right chest/arm/shoulder and spread outwards. I had pericarditis a few times also.
It's also possible that viral infection of nerves causes nerve integrity to fell, letting positive ions flow into the cells and causing the above issues.
Recently I've been getting nocturnal seizures that only happen during dreams. Over 10 seconds, I get an increasing intensity in my right head, like a car slowly revving up, and at the same time I get increasingly loud tinnitus.
I don't know, I feel like you and I may be part of a similar CFS phenotype, not the same as a few others.